Extruder



G. E. GLISS Sept. 29, 1953 EXTRUDER Filed Dec. 28, 1951 lNl/E/VTOR G. E. GL/SS ATTORNEY Patented Sept. 29, 1953 UNITED STATES PATENT GFFECE EXTRUDER.

George E. Gliss, Baltimore, Md., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York 6 Claims.

This invention relates to extruders, and more particularly to extruders for individually covering a plurality of conductors simultaneously.

In the manufacture of covered conductors, it has been the common practice to extrude each covering. over single or dual conductors with a single extruder. However, in covering wires having small conductive cores with relatively thin insulating coverings, it has not been economically feasible to provide extruders which do not extrude much larger capacities than that required to cover single or double wires. Multiple head extruders have been proposed, but it has been necessary heretofore to stop the entire apparatus when one wire source has run out or a wire has broken to prevent clogging up of the extruding head associated with that wire. An object of the invention is to provide new and improved extruders.

Another object of the invention is to provide new and improved apparatus for extruding individual coverings on a plurality of conductors.

A further object of the invention is to provide multi-head extruders for simultaneously applying individual coverings on a plurality of conductors.

An apparatus illustrating certain features of the invention may include an extruding head in which a core tube and a die are mounted in alignment. Means are provided in the head for closing off the core tube to prevent leakage of compound when there is no core being advanced through the head.

A complete understanding of the invention may be obtained from the following detailed description of an apparatus forming a specific embodiment thereof, when read in conjunction with the appended drawings, in which Fig. 1 is a front elevation of an apparatus forming one embodiment of the invention;

Fig. 2 is a vertical section taken along line 2-2 of Fig. 1;

Fig. 3 is an enlarged, fragmentary, side elevation, partly in vertical section, of a portion of the apparatus shown in Fig. 1;

Fig. 4 is a fragmentary elevation looking in the direction of the arrows 4-4 in Fig. 3, and

Fig. 5 is 'a view similar to Fig. 4 with some elements of the apparatus shown in different positions from those in which they are shown in Fig. 4.

Referring now in detail to'the drawings, there is shown therein a multi-head extruder for extruding individual coverings IB| on conductors il--II simultaneously. The extruder includes an extruding cylinder I4 having a bore l therein, in which is mounted a stock screw 16 having a tapered root. A plastic compound,

including as the essential ingredient thereof a thermoplastic material such as, for example, a copolymer of vinyl acetate and vinyl chloride, polyvinyl acetate, polyethylene, polyvinyl chloride, vinylidene chloride or the like, is inserted into the bore 15 through a hopper ll. The screw it advances the compound along the cylinder I l toward the lefthand end thereof, as viewed in Fig. 1, and forces it into an extruding head 20 which is supported at one end by a standard 2|.

The extruding head 26 is provided with a cylinder 22 having a. bore 23 therein, in which a ribbed stock screw extension 2% is rotatably mounted and fits fairly closely. The extruding head 20 also includes branch conduits 262i5 leading from the topand bottom of the cylinder 22, into which the plastic compound is forced in extrudable condition by the pressure of the screw It thereon. Individually adjustable reducing and shutting-off valves 3ll3ll are connected to the branch conduits 2626 and to flanged sub-heads 3l3|. Each sub-head 3| (Fig. 3) includes a passage 32 leading to a transverse passage 33, in which is mounted a die holder 34 and a core tube holder 35. A retaining plate 36 secures the die holder 34 in the passage 33, and a die 37 is mounted in a counterbore 38' formed in the di holder 34.

An annular, interiorly and exteriorly threaded plug 49 secures the core tube holder 35 in the passage 33, and the core tube holder holds a core tube 4| in properly oriented position with respect to the die 31. A key 45 keys the core tube holder 35 in the passage 33, and a pin 4:; secures the core tube 4| against rotation relative to the core tube holder. The core tube holder is provided with a central passageway 46 aligned with a passageway 41 in the core tube through which the conductor ll may be advanced.

A bore 50 formed in the core tube holder is eccentric with respect to the bore 46, and is designed to receive a plug 5! having a threaded portion 52 threaded into a tapped bore 53 formed inthe plug 46. The plug 5| is provided with a passage 55 eccentric to the longitudinal axis thereof, and, when the plug 5! is in one position with respect to the core tube holder 35, the passage 55 is aligned with the passage 46 in the core tube holder. However, when the plug Si is screwed completely into the bore 59, the end of the plug 5| abuts the end of the bore 50, and the passage 55 is completely offset from.

the passage 46. A pin 51 projects through a bore 58 formed in the plug into a bore 59 formed in the core tube holder 35 to key the core tube holder to the plug 4!! in an oriented position with respect thereto.

Operation The conductors Hil are continuously advanced through the sub-heads 3I3l by suitable means (not shown), and the plastic compound fed into the hopper I1 is continuously,- advanced along the extruding cylinder [4 and is simultaneously worked and heated to a condition of high extrudability. by the stock screw 16 and the stock screw extension 24; The stock screw it forces the highly plastic compoundintothe branch conduits 26-26 through the valves til-36 and into the sub-heads' 3l-3l, through which the compound flows around the core tubes 4l4l and through the -,dies 3'l3l, which form the compound into the coverings Ill-l on the wires H-l I.

In the event of breakage or. running out of the conductor 1 i of one of the sub-heads 3 i-3i; and it is undesirable to shut down that head, the plug of the head is threaded farther into the bore Mito seat against the end of the bore "in'the core tube holder 35: This effectively shuts off flow of the compound back through the core'tube and the conductor entrance end of the subhead 3 1. Then when another conductor is ready, the plug 5| may be turned back to align the'passage. therein with the passage 46 in the core tube holder 35,.and the conductor may be'pushed through the plug 5|, the core tube holder 35, the core tube H and the die 31; kept outof the conductor entrance ends of the sub-heads during stringing, up operations;

The aboveedescribejd apparatus serves to extrude a multitude of individual coverings on a Ihus, compound is and arranged that when the cylindrical plug abuts the end of the eccentric socket, the passages in the core tube holder and the cylindrical plug are offset one from another.

2. An extruder, Which comprises an extruding head having .a passage th'erethroug'hj a die mounted in the delivery'end-of thepassage, a core tube holder having a core passage extending along the axis thereof mounted in the entrance 'g-endw of the passage, said holder also being provided with a socket at the entrance end thereof eccentrictothe'axis thereof, a core tube held by the core" tube" holder, a plug having a passage therethrough eccentric to the longitudinal axis thereof mo unted rotatably in the socket in the core tube holder, and means selectively operable for holding the plug in. a position in which the plug abuts the end of the socket and the passage in the plug is offset from thepassage'in'the' core tube holder.

3. An extruder, which comprises an extru'd ing headhaving a passage therethroug-lLa die mounted in one end of the passage,- a, core-tube mounted in theother end of the passage provided with a bore and a counterbore'at the entrance endthereof eccentric to the bore, and a cylindrical plug having an eccentric bore therein mounted movable between a position-in Which thebore multitude of small wires with about the same (2;:

plug having an eccentric bore'therein mounted rate of speed for eachwire and with the same size of extruder as normally is required 'to extrude a similar heavier covering over one conductor or another core. Consequently, large savings in equipment and floor space may be eifected'by this apparatus.

Certain. features of the above described'appa ratus are disclosed and claimed in copending application Serial No.,263,7,5 2, fiJed'DecemberZB, 1951, by G. E. I-Ienning for Extruder.

t is to be understood thatthe above-described arrangements are simply illustrativeof the 'appli'-. cation of the principles of the invention. Numerous other arrangementsmay be readily detherethrough is aligned with-the herein the core tube and a position closing the bore in the 'core tube.

4; An extruder, which comprises-an extruding head having a passage-therethrough, a die mounted in one end of the passage, a core tube mounted in the other end of the passage provided with a bore and a counterbore at the'entrance end thereof eccentric to thebore, a cylindrical in the counterbore, and-means operable selectively for moving the plug betweena position in which the bore therethrough is aligned with the bore in the coretube and a position closing the passages connected to the outlets, a plurality of vised bythose skilled in the art which will i embody the principles of the invention andfall within the spirit and scope thereof.

What is claimed is:

1. An extruder, whichcomprises anextruding head having a passage therethrough andalso-- I provided with a tapped counterbore-at the entrance end of the passage, a die mounted in the delivery end of the passage, a core tube holder having a core passage extending along. the axis thereof mounted in'the entrance end of the pas tube mounted in the last-mentioned counterbore,

an internally tapped annular plug mounted in the threaded counterboreinthe extruding. head, and a cylindrical plug having a passage'therethrough eccentric to the longitudinal axis thereof threaded through'the annular plug into the .ec- I centric socket in the core tube holder,- -said plugs and said core tube, holder, being so constructed P dies mounted-in the passagesaplurality of core tubes having bores therethroughmounted' in the passages, said core tubes also being provided'with counterboreseccentric to the'bores, anda plurality'of cylindrical plugs-having eccentric bores therethrough mounted rotatably in the counterbores in the core tubes;

6. An extruder, which comprises an extruding cylinder, an extruding headhaving a- T-shaped passage connected to the cylinder, 5], die mounted in the passage, a core tube-having a bore therethrough mounted in the passaga'said-core tube also being provided with a counterbore eccentric to the bore, and a cylindrical plug having an eccentric bore therethrough mounted rotatably in the counterbore in thecore tube;

GEORGE-E. GLISS.

References Citedeinthe: fileof this. patent UNITED STATES PATENTS Numberv Name Date? 79,896 Bishop July 1 2,1868 253,822 Mignon Feb. 14, 1882 1,154,674 Van Ness Sept. 28,1915 1,646,825 Kochendorfer Oct.25, 1927 2,452,610. Sonnenfe1d' Nov -2, 1948 

